Hitherto, it is known to cast a cylinder head of an engine for a vehicle by a low pressure die casting method. As a casting machine for this low pressure die casting method, it is known to adopt a configuration in which a molten metal furnace is arranged under a mold composed of an upper mold and a lower mold having a sprue, and the molten metal stored in the molten metal furnace is pushed up by applying pressure and supplied to the inside of the mold via a stoke (supply conduit) through the sprue of the lower mold.
In this type of casting machine, in a case of producing a product having a complicated shape which cannot be casted only by the upper mold and the lower mold, a horizontal sliding mold is used in addition to the upper mold and the lower mold (for example, refer to Japanese Patent Application Laid-open No. 2013-86118). As a casting machine using the horizontal sliding molds, there is known to arrange the horizontal sliding molds along the four sides of a rectangular lower mold so as to enable reciprocating motion while sliding on a rail between a mold-closing position and a mold-opening position. A lower section of the horizontal sliding mold closely contacts the lower mold, and the side section of the horizontal sliding mold closely contacts the adjacent horizontal sliding mold at the mold-closing position.